1. Field of the Invention (Technical Field)
The present invention relates to a horizontally reversible insulating concrete form with opposing panels connected by wire ties, preferably welded wire ties with a metal sheet attachment stud, used to make concrete structures.
2. Description of Related Art
Traditional concrete walls in building construction are generally made by setting up two parallel form walls and pouring concrete into the space between the forms. After the concrete hardens, the builder then removes the forms, leaving the cured concrete wall.
This common prior art technique has significant drawbacks. The resulting wall is not insulated, and significant labor is required to remove the forms after the concrete cures or hardens.
Techniques have developed for forming modular concrete walls that use a foam insulating form material, generally referred to as “insulating concrete forms” or by the acronym “ICF”. Using modular forms, which are available in different sizes, walls are set up. Most insulating concrete forms are composed of two parallel panels, forming an exterior and interior wall panel, with ties, bridges or other connecting components holding the two panels in place relative to each other while concrete is poured into the cavity between the panels. The insulating form panels remain in place after the concrete cures. Thus no labor is required to either remove forms or add insulation, resulting in substantial efficiency. In most cases, the insulation of the form provides adequate insulation for the building, so that no additional insulation is required.
Insulating concrete forms are manufactured from a polymeric material, often polyurethane or polystyrene, which is expanded and formed within a mold to yield a rigid, low-density foamed plastic form having vertical and/or horizontal cavities to be filled with wet concrete. U.S. Pat. No. 3,552,076, entitled Concrete Form to Gregori, and U.S. Pat. No. 3,788,020, entitled Foamed Plastic Concrete Form With Fire Resistant Tension Member, also to Gregori, are two early patents that both teach methods whereby polystyrene foam is molded to yield a concrete form.
The construction industry has incorporated several means of attaching finishing materials to the outer sides of these molded construction forms after the concrete within the cavities has set. One such method has been to glue the paneling, sheetrock, or other suitable finishing materials to the outer surfaces of the completed form. Additionally, outer finishing materials may be rigidly attached using a penetrating device through the outer molded form to the cured concrete or other building material inside the form. Another method to attach finishing materials is to glue or nail furring strips on the outer surfaces of the forms. Gluing the furring strips to the foam forms require construction adhesive, and nailing the furring strips or the finishing materials to the outer sides of the forms require that special concrete nails be used. The application of these concrete nails, moreover, must be accomplished at a critical time during the curing of the concrete. Then, the finishing materials are nailed or screwed onto the furring strips.
Another approach to concrete forms is disclosed in U.S. Pat. No. 4,223,501, entitled Concrete Form, to DeLozier. This patent teaches a method whereby a one piece transverse connecting member is embedded in the polystyrene concrete form taught in the Gregori patent. The connecting member has attachment flanges extending at right angles which extend near the outer surfaces of the form.
U.S. Pat. No. 4,879,855 entitled Attachment and Reinforcement Member for Molded Construction Forms, to Berrenberg, discloses an attachment and reinforcement tie for molded construction forms with a central portion of expanded steel in which the ends are bent to accommodate covering strips of solid galvanized steel. The tie is embedded in a molded construction form during the form's manufacture. The strips of the solid galvanized steel extend to the outer surfaces of the form and provide attachment surfaces while the central portion of expanded steel web reinforces the form and connects the two panels.
It is known to have a groove on one end of both panels in an ICF, with a corresponding tongue on the other end of the panels, such that two forms may be joined together in a horizontal plane by means of a tongue and groove attachment. Among other patents, U.S. Pat. Nos. 3,552,076, 3,788,020, 4,223,501, 4,698,947, 4,879,855, 5,459,871, 5,465,542, and 5,596,855 disclose forms of this type. Other patents disclose a shiplap joint on the ends of both panels in an ICF, as disclosed in U.S. Pat. Nos. 4,516,372 and 5,568,710. However, all such forms can only be interconnected in a horizontal dimension in a specific direction, and the forms are not reversible.
While many forms utilize a plastic tie, there are a few forms which utilize a metal tie, such as U.S. Pat. Nos. 4,879,855 and 5,568,710, which employ an expanded metal tie, U.S. Pat. Nos. 4,223,501 and 5,596,855, which employ perforated metal plates with comparatively small openings, and U.S. Pat. No. 4,967,528, which employs a metal wire requiring an external clip to fasten the wire to an external plate. However, all such forms have significant limitations. With most, the openings through the tie are sufficiently small so as to impede the free flow of concrete during pouring. With forms such as the '528 form, multiple parts are required, and the tie is limited to providing connection at the top and bottom of the form, and thus provides inadequate strength for many form heights.
There remains a need in the industry for an insulated concrete form with superior strength that provides minimal obstruction to concrete flow when pouring. In general, having a form with ties on close centers, such as every six or twelve inches, is preferable. However, if the tie component can obstruct the flow of concrete when being poured, void or vacant spots can result which can seriously weaken the resulting wall. There similarly remains a need in the industry for a form which is reversible such that it may be assembled in a horizontal dimension in any orientation, with no “inside” or “outside” orientation to the form.